Neighborhood Socioeconomic Disadvantage is Associated with Mortality in Older Veterans Following Spine Surgery

Introduction: Nearly one-third of older Americans suffer from lumbar degenerative spine disease (DSD). Although risk of adverse outcomes exists, spinal surgery to relieve pain and preserve independence among older adults with DSD is increasing. The extent to which adverse outcomes vary by patient-level (e.g., race/ethnicity, income, education) and contextual-level (e.g., living in highly deprived neighborhoods, rurality) have been scarcely investigated in spine surgery.

Methods: We assessed the associations of patient-level and contextual-level factors with adverse outcomes, risk adjusting for clinical factors, in a retrospective cohort of 5,053 Veterans aged >65 years who underwent inpatient spine surgery for DSD from 2013-2019. VA Surgical Quality Improvement Program data were merged with VA and Medicare administrative data. The associations of race/ethnicity, rurality, block group Area Deprivation Index (ADI) with 30-day mortality, 30-day readmission, and postoperative complication were tested. ADI integrates 17 variables (e.g., income, education, employment, housing quality), providing a neighborhood ranking by socioeconomic disadvantage (ADI>85 is highly disadvantaged).

Results: Mean age was 70.7 years; 76.8% identified as white, 16.1% black, 7.1% were other race. Veterans lived in rural (35.4%) and in highly deprived neighborhoods (ADI>85, 12.4%). Readmission and mortality were 11% and 0.9%, respectively and 9.7% experienced postoperative complications. In multivariable models, living in a highly deprived neighborhood was associated with mortality (OR=2.87; 95%CI 1.48-5.56, p=0.002). Frailty and comorbidity were associated with mortality, complication and readmission; emergent/urgent status with complication and readmission (p < 0.05). When controlling for clinical factors and age, living in a highly deprived neighborhood continued to be associated with increased mortality (OR=2.86; 95%CI 1.48-5.54, p=0.002). Age, race/ethnicity and rurality were not associated with increased risk of adverse outcomes.

Conclusion : Living in a highly deprived neighborhood was a drastic risk factor for spine surgery 30-day mortality. However, clinical factors also played a role. Mechanisms to address socioeconomic disadvantage need to be explored to improve outcomes.